Variable Valve Timing

The valve timing (camshaft phasing) is infinitely variable within the maximum design limits of advance and retard.
An actuating shuttle valve directs engine oil pressure to either side of the control piston within the VVT unit to advance or retard the intake camshaft, as calculated and controlled by the ECM. Movement of the actuating shuttle valve is by a linear solenoid.
Closed loop sensing and control of each intake camshaft is provided by the ECM in response to signals from each camshaft position sensor.